I've got a problem with arcing *I think. I can hear clicking from what sounds like electrical arcing under the hood and I sometimes get a mild shock from touching metal surfaces inside the truck.
If you're feeling a shock, it's not a 12V problem. That's not enough voltage to feel, unless you're using your tongue. Like the other guys suggested, concentrate on your high voltage ignition wires and the distributor. What you're probably hearing is a short to ground from one of the spark plug wires.
